A discogram involves the injection of x-ray contrast into the intervertebral disk. Discography is performed to determine which disk level(s) is painful in certain patients who have back or neck pain caused by disc degeneration. Discography is used as an additional diagnostic tool for your surgeon when x-ray studies are insufficient. In general, a minimum of two disks will be injected. If you have x-ray findings of disk problems at many levels you may need more disks injected. A discogram is only a test and does not treat the underlying problem.